Bipolar electrode having irregularity at inserting end thereof and method of insertion



June 23, 1970 B. ACKERMAN BIPOLAR ELECTRODE HAVING IRREGULARITY ATINSERTING END THEREOF AND METHOD OF INSERTION Flled March 5, 1969INVENTOR. BERNARD ACKERMAN .s V.. E N /n o T T WA Y/ UD United StatesPatent O BIPOLAR ELECTRODE HAVING IRREGULARITY AT INSERTING END THEREOFAND METHOD F INSERTION Bernard Ackerman, Metuchen, NJ., assignor toElectro- Catheter Corporation, Rahway, NJ., a corporation of New JerseyContinuation-impart of application Ser. No. 480,020,

Aug. 16, 1965. This application Mar. S, 1969, Ser.

Int. Cl. A61m 1/04 U.S. Cl. 128-418 5 Claims ABSTRACT OF THE DISCLOSUREA bipolar electrode apparatus comprising a flexible inner conductiveelement and a ilexible outer conductive element fabricated from anextremely flexible and resilient coil spring. An insulating element isdisposed between said llexible inner and outer conductors. The outerconductive element is formed having a bend in the form of an elbow atone end thereof. The bipolar electrode apparatus is adapted forinsertion through the chest wall into the ventricular cavity in cases ofcardiac arrest. The elbow provides an irregularity in the apparatus suchthat a physician can readily ascertain, by frictional drag, when theapparatus has penetrated a suicient distance into the ventricularcavity. The resiliency of the elbow permits the electrode to bepositioned immediately adjacent the interior wall of the heart and thusmake positive contact therewith.

This application is a continuation-in-part of co-pending applicationSer. No. 480,020, '.tiled Aug. 16, 1965.

The use of bipolar electrodes for insertion into the ventricular cavityfor the purpose of restarting the heart function by the transmissionthereto of electrical impulses has been disclosed and claimed in patentapplication Ser. No. 480,020, iiled Aug. 16, 1965. Thus, and asdescribed in greater detail in the aforementioned application, a bipolarelectrode pair may comprise an electrode Wire coated with insulatingmaterial though bared for purposes of electrical contact at either endthereof. The second electrode of the pair is in the form of an extremelyflexible and resilient coil spring which, to all intent and purposes, iscoiled closely around the inner insulated electrode.

The electrode pair is inserted into the ventricular cavity by puncturingthe chest wall and the wall of the heart with a needle of conventionalstructure. The needle comprises a cylindrical sheath or sleeve in whichis inserted a substantially rigid pointed needle to achieve puncturewithout clogging the sleeve portion. After puncture is achieved, theneedle portion is withdrawn and the electrode pair inserted through thesleeve portion into the ventricular cavity. The sleeve is then withdrawnleaving the bipolar electrode pair in place.

Although this novel electrode pair constituted a considerable advanceover the prior ait, it left unresolved two important matters in thisclinical procedure. First, the inserting physician could not readilydetermine, except by the provision of markers, when the electrodes hadbeen inserted a suicient distance into the ventricular cavity.Furthermore, he could not determine with accuracy, except by the use ofX-ray observation, whether proper electrical contact was being achievedinside the cavity.

The bipolar electrode of the present invention is similar to theelectrode pair of the aforementioned application but is constructed soas to have a linear irregularity close to the end thereof which isinserted into the venrice tricular cavity. The purpose of thisirregularity is to increase the drag on the electrode as it passesthrough the sleeve of the inserting needle. This drag will ceaseabruptly when the portion of the electrode at which the irregularity islocated passes out of the needle sleeve. Then, simply removing thesleeve portion or the cannula of the needle places the tip or distal endof the stylet against the endocardium automatically. It is disclosed inthe aforementioned application Ser. No. 480,020 that the outer electrodeis fabricated of an extremely flexible and resilient coil spring which,to all intent and purposes, is coiled closely around the inner insulatedelectrode. The resiliency of the outer electrode, in conjunction withthe permanent linear irregularity adjacent the distal end of theelectrode pair defines an unbiased or unstressed position or conditionfor that part or portion of the electrode pair between the distal endand the linear irregularity thereof. As will be explained in greaterdetail hereinafter, this portion of the electrode pair, in its unbiasedor unstressed condition, defines an angle with the remainder of thestylet of the present invention, and while the angle subtended betweenthese two portions is not critical, the angle is preferably acute.Accordingly, the cessation of the frictional drag resulting from thelinear irregularity exiting the cannula of the needle enables theportion of the electrode pair between the distal end and the linearirregularity to automatically return to its unbiased or unstressedcondition in which an angle is subtended between that portion and therest of the stylet. As a result, and as hereinbefore pointed out, thedistal end or tip of the stylet is automatically placed against theendocaridum. Preferably, and as will also be described in greater detailhereinafter, the entire portion between the distal end of the stylet andthe linear irregularity is disposed adjacent the endocardium, and thisis accomplished, after the distal end is automatically placed againstthe endocardium, by withdrawing the cannula, and by applying a gentlewithdrawing force to the stylet itself. When the linear irregularityencounters the endocardium, the attending physician will experience anincrease in the withdrawing force necessary to continue to withdraw theelectrode pair, thus recognizing the location of the linear irregularitywith respect thereto.

The present invention therefore enables an attending physician toautomatically place the distal end or tip of the stylet or electrodepair against the endocardium, and also enables the physician to readilyascertain the position of the linear irregularity with respect thereto.Furthermore, the physician is enabled to place the portion of theelectrode pair or stylet between the distal end or tip and the linearirregularity substantially adjacent to the endocardium with much greaterease and facility. Additionally, and because the distal end or tip ofthe stylet is automatically placed against the endocardium, the regionof highest current density, located at the distal end or tip of thestylet, will be placed closest to the endocardium so that the electricalstimulation has the highest possibility of successful capture. This istrue because the materials from `which the electrode pair of thisinvention are fabricated present lesser resistance to the passage ofelectrical current than the blood within the body, the tissue thereof,and the like.

In accordance with the principles of the present invention, therefore,procedures of this type can thus be eiected more rapidly and with muchgreater facility because the linear irregularity or distal curve of thisinvention will enable the attending physician to easily feel when thelinear irregularity of the electrode pair clears the tip of the cannulaof the needle and has entered the ventricular cavity or, for thatmatter, any other portion of the body under examination.

short distance from the distal end, that is,` the end to be inserted.While the bend angle is not critical, it is preferred that an acuteangle is subtended between the end of the electrode and main bodythereof. Since this bend is in a substantially flexible body, theelectrode may be temporarily straightened during passage through theneedle sleeve. However, even in its straightened condition, the bendproduces the necessary irregularity to generate the desired frictionaldrag. When the portion of the electrode having the bend therein passesout of the needle sleeve, the bend portion will automatically springinto its desired position placing the region of highest current densityadjacent the inner wall of the organ punctured, while at the same timeeliminating the frictional drag such that the physician will be sure ofproper placement.

Accordingly, it is an object of the instant invention to provide abipolar, flexible electrode pair and a method of inserting same, havingan irregularity at one end thereof whereby an inserting physician caneasily determine when the electrode pair has been inserted in the bodythe desired amount.

Another object of the instant invention is to provide such a bipolarelectrode pair wherein such irregularity automatically places orpositions the region of highest current density adjacent or against theinner lwall of the organ punctured, so that the electrical stimulationhas the highest probability of successful capture.

Still another object of the instant invention is to provide such anelectrode pair wherein the aforementioned irregularity is defined `by abend provided at one end thereof.

Yet another object of the present invention, in addition to all of theforegoing objects, is to provide bipolar electrode apparatus having anirregularity at one end thereof whereby an inserting physician caneasily determine when the electrode pair has been inserted in the @bodythe desired amount, said irregularity automatically placing orpositioning the region of highest current density adjacent or againstthe inner wall of the organ punctured, to present the highestprobability of successful capture of electrical stimulation, and, inaddition, to avoid accidental dislodgement of said bipolar electrodeapparatus.

The present invention will best be understood, and objects and importantfeatures other than those specifically enumerated above, will becomeapparent when consideration is given to the following detaileddescription, which, when taken in conjunction with the annexed drawings,describes, discloses, illustrates and shows a preferred embodiment ofthe present invention and what is presently considered to be the bestmode of practicing the principles thereof. Other embodiments ormodifications may be suggested to those having the benefit of theteachings herein, and such other embodiments or modifications areintended to be reserved especially as they fall within the scope andspirit of the subjoined claims.

In the drawings:

lFIG. 1 shows the end portion of a bipolar electrode apparatusconstructed in accordance with the instant invention.

FIG. 2 illustrates a puncturing needle and sleeve useful for insertingthe electrode apparatus of FIG. l.

FIG. 3 illustrates the needle sleeve with the electrode apparatus of theinvention passing through an illustrative wall which could be anyportion or organ of the body; and

FIG. 4 illustrates the electrode apparatus operating position on theinner side of the wall and connected to the impulse generator.

With reference to the drawings, there is illustrated therein oneparticular embodiment of electrode apparatus constructed in accordancewith the principles of the present invention. It is generally designatedby the reference character 10. Before going into detail, it is to beunderstood that although the invention is described herein withreference to the therapeutic application of electrical current to theheart, the apparatus may equally be utilized as a monitoring device.Similarly, the applicability of this apparatus is in no way limited tothetreatment or diagnosis of the heart. It may Ibe utilized in theinterior of any portion of the vbody where diagnostic measurements orthe application of externally generated electrical pulses may beconsidered desirable.

In FIG. l, there is illustrated the bipolar electrode apparatus 10 whichcomprises a first or inner electrode 12 which terminates at one endthereof in a hook or loop 14. The inner electrode 12 may lbe fabricatedof any suitable electrically conductive material and is coated with aninsulating sheath 22 which coats substantially the entire length of theelectrode 12 with the exception of exposed tip 14 and the other end 15which is to be connected to the pulse generator 575 (see FIG. 4).

The second or outer electrode 16 of the electrode apparatus 10 isfabricated of suitable, electrically conductive material in the form ofan extremely flexible and resilient coil spring, the coils of whichsurround the insulating layer 22. The outer electrode 16 extendssubstantially as far as the tip 14 but is separated therefrom by a rigidjoint of non-conductive material 18, which is fabricated of any suitablematerial, an epoxy resin or the like. It will be appreciated that theinsulative sheath 22 and the tip 18 prevents the shorting of electrodes12 and 16.

In the preferred modification of the invention, the bipolar electrodeapparatus 10 is bent into the shape of an elbow at 17. This bend may Ibeintroduced into the bipolar electrode apparatus 10 in any suitablematter, such as, for example, by a suitable process for applying heat.As will ibe further described, this Ibend is such that the entire lengthof the apparatus 10 may be temporarily straightened during the insertionprocess; but upon release of the defiecting force, the unit will againreturn to the elbow shape.

In FIG. 2 there is illustrated a composite puncturing needle 42comprising an inner needle or stylet 50 having a pointed tip 51 at oneend thereof and an enlarged head 52 at its opposite end. The innerneedle 50 is removably inserted in a cylindrical sleeve or cannula 53which terminates in an enlarged, substantially hollow head 54.

In the operation of the device as applied to the heart, the needle 42 ispassed through the chest wall substantially at the fourth and fifthintercostal space (occurring between the ribs of the torso) and furtherpassed through the ventricular wall 47 until it enters the ventriclecavity 48. This may 4be the left ventricle of the heart.

The inner needle or stylet 50 is then removed and the electrodeapparatus 10 is passed into the sleeve portion or cannula 53 via thehollow head 54. Because of the elbow 17, some difficulty may beexperienced in guiding the unit 10 into the sleeve portion S3. Thisinsertion may be facilitated by initially inserting the unit 10 into asmall length of tubing `49 having an internal diameter approximatelyequal to that of sleeve 53. Tube 49 is then inserted into head 54 andplaced adjacent to the beginning portion of sleeve S3. Unit 10 may thenbe easily slid into sleeve 53.

It will be understood that due to the distortion of elbow 17 a certainamount of frictional resistance will be felt while unit 10 is pushedthrough sleeve 53. This resistance will cease as soon as elbow 17 passesout of the end of sleeve 53 inside the ventricular cavity 48. Therefore,in a very simple manner, the physician will be apprised of the fact thatthe apparatus has reached the desired depth in the body.

Then, simply removing the sleeve or cannula 53 by withdrawing it fromthe ventricular cavity 48 and from the chest `wall will automaticallyplace or position the tip 14 of the electrode pair or stylet 10 againstthe endocardium. That is, and as hereinbefore pointed out, the coilspring from which the outer electrode of the stylet of this invention isfabricated introduces a certain resiliency which, when taken inconjunction with the linear irregularity or elbow 17 results in thatportion of the stylet between the distal end and the elbow having anunbiased or unstressed condition enabling the aforesaid portion todefine an angle with respect to the remainder of the stylet. When theelbow 17 exits from the sleeve or cannula of the needle, the resiliencyof the coil spring and the elbow 17 automatically causes the portion ofthe stylet @between the distal end or tip and the elbow to tend toreturn to its unbiased or unstressed condition` This automaticallyplaces the distal end or tip against the endocardium.

In addition, cessation of the frictional drag resulting from the elbow17 passing through the cannula 53 enables the attending physician torecognize that the elbow 17 has, indeed, entered into the ventricularcavity'. If the attending physician will now withdraw the cannula 53,and then apply a gentle withdrawing force to the stylet, the physicianwill find it necessary to increase his withdrawing force when the elbow17 approaches a position against or substantially adjacent theendocardium. In this manner, the attending physician will be able toposition the aforesaid portion of the stylet between the distal end ortip 14 and the elbow 17 substantially adjacent the endocardium along thelength of that portion.

It will be understood that automatically placing the distal end or tip14 of the stylet 10 of this invention against or substantially adjacentthe endocardium places the region of highest current density in such aposition with respect thereto that the electrical stimulation,hereinafter to be described, has the highest probability of successfulcapture. This is true because the materials from which the electrodes ofthe present invention are fabricated have lesser resistance to thepassage of electrical current than the blood within the body, thetissues thereof, and the like. For these reasons, it is the distal endor tip 14 that is the region of highest current density.

In addition to achievinf7 the foregoing objects, the present invention,in general, enables procedures of this type to be effected more rapidlyand with much greater facility because the linear irregularity or distalcurve at the elbow 17 enables the attending physician to easily feelwhen it clears the end of the needle sleeve or cannula, and has enteredthe ventricular cavity or, for that matter, any other portion of thebody under examination.

An impulse generator 55 is then connected to the inner electrode 12 bylead 56 and to the outer electrode 16 via lead 58. Electrical current ofthe desired strength and frequency may then be applied through thecircuit which comprises inner electrode 12, the tip 14 thereof, the Wallof cavity 48, and outer electrode 16.

While the invention has been shown, illustrated, described and disclosedin terms of embodiments or modifications which it has assumed inpractice, the scope of the invention should not be deemed to be limitedby the precise embodiments or modifications herein shown, illustrated,disclosed or described, such other embodiments or modifications intendedto be reserved especially as fi they fall within the scope of the claimshere appended.

What is claimed is:

1. A bipolar electrode apparatus comprising, in combination, an innerand an outer electrically conductive element, an insulating elementdisposed between said inner and outer electrically conductive elements,said insulating element terminating at a region beyond which a currenttransmitted to said outer electrically conductive element will betransmitted to said inner electrically conductive element, said innerelectrically conductive element cornprising an electrode fabricated of aflexible material, said outer electrically conductive element comprisingat least one coil spring fabricated of an extremely flexible andresilient material, and said apparatus having an elbow formed near oneend thereof and defined by a short length of said bipolar electrodeapparatus being disposed in nonalignment with the remaining lengththereof when said apparatus is in its natural configuration.

2. A bipolar electrode apparatus as defined in claim 1, wherein theangle subtended by said elbow is an acute angle.

3. A bipolar electrode apparatus as defined in claim 1, wherein saidinsulating element is fiexible about at least the elbow portion of saidapparatus.

4. Method of automatically positioning the region of highest currentdensity of bipolar electrode apparatus adjacent the wall of a body toenable electrical stimulation applied to said body to present thehighest probability of successful capture, comprising the step ofpuncturing said Wall with a needle comprising a pointed inner portionand an outer sleeve portion; withdrawing said pointed inner portion;inserting bipolar electrode apparatus having an irregularity near oneend thereof into said sleeve portion until the frictional resistancegenerated by said irregularity disappears; and removing said sleeveportion from said wall.

5. Method as defined in claim 4, comprising the steps of initiallyinserting said bipolar electrode apparatus into a guide tube; andplacing said guide tube substantially adjacent the sleeve portion ofsaid needle to facilitate the passage of said electrode apparatus intothe sleeve portion, enabling procedures contemplating the use of bipolarelectrode apparatus to be effected more rapidly and with the greatestfacility further enabling a distal end of said bipolar electrodeapparatus to be placed adjacent to or against the wall of a bodyautomatically upon removing said needle.

References Cited UNITED STATES PATENTS 2,022,065 11/1935 Wappler 12S-4072,496,111 1/1950 Turkel 128-2 3,087,486v 4/ 1963 Kirkpatrick 12S-418OTHER REFERENCES Zuder et al.: Journal of American Medical Association,vol. 184, No. 7, May 18, 1963, pp. 13S-138.

WILLIAM E. KAMM, Primary Examiner

